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8.2/8.3 Parallelograms. Vocabulary. Parallelograms. What You'll Learn. You will learn to identify and use the properties of parallelograms. 1) Parallelogram. In parallelogram ABCD below, and . B. A. D. C. Parallelograms. parallel sides.
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Vocabulary Parallelograms What You'll Learn You will learn to identify and use the properties of parallelograms. 1) Parallelogram
In parallelogram ABCD below, and B A D C Parallelograms parallel sides A parallelogram is a quadrilateral with two pairs of ____________. congruent Also, the parallel sides are _________. Knowledge gained about “parallels” (chapter 4)will now be used in the following theorems.
A A A B B B D D D C C C Parallelograms Opposite angles of a parallelogram are ________. congruent A C and B D Opposite sides of a parallelogram are ________. congruent The consecutive angles of a parallelogram are ____________. supplementary mA + mB = 180mD + mC = 180
In RSTU, RS = 45, ST = 70, and U = 68. S R 45 70 U T 68° Parallelograms Find: RU = ____ 70 Theorem 8-3 45 UT = _____ Theorem 8-3 68° Theorem 8-2 mS = _____ 112° Theorem 8-4 mT = _____
In RSTU, if RT = 56, find RE. A B R D S C E U T Parallelograms bisect E RE = 28
A B D C Parallelograms In the figure below, ABCD is a parallelogram. Since AD || BC and diagonal DB is a transversal, then ADB CBD. (Alternate Interior angles) Since AB || DC and diagonal DB is a transversal, then BDC DBA. (Alternate Interior angles) DB BD ASA Theorem
A B D C Parallelograms congruent triangles
Parallelograms The Escher design below is based ona _____________. parallelogram You can use a parallelogram to make a simple Escher-like drawing. Change one side of the parallelogram and then translate (slide) the change to the opposite side. The resulting figure is used to make a design with different colors and textures.
Parallelograms End of Section 8.2
Vocabulary Tests for Parallelograms What You'll Learn You will learn to identify and use tests to show that a quadrilateral is a parallelogram. Nothing New!
A B C D Tests for Parallelograms congruent
In quadrilateral PQRS, PR and QS bisect each other at T. P Q T S R Tests for Parallelograms You can use the properties of congruent triangles and Theorem 8-7 to find other ways to show that a quadrilateral is a parallelogram. Show that PQRS is a parallelogram by providing a reason for each step. Definition of segment bisector Vertical angles are congruent SAS Corresp. parts of Congruent Triangles are Congruent Theorem 8-7
A B C D Tests for Parallelograms parallel congruent
A B E D C Tests for Parallelograms bisect each other
A B D C Tests for Parallelograms Determine whether each quadrilateral is a parallelogram.If the figure is a parallelogram, give a reason for your answer. Given Alt. Int. Angles Therefore, quadrilateral ABCD is a parallelogram. Theorem 8-8
Tests for Parallelograms End of Section 8.3